The present invention relates to a location information management system for a mobile station (hereinafter xe2x80x9cmobile terminalxe2x80x9d) in a mobile switching network.
In general, a mobile switching network is comprised of a plurality of base stations each communicating wirelessly directly with mobile stations (hereinafter xe2x80x9cmobile terminalsxe2x80x9d) in its service area, a plurality of subscriber accommodating centers each accommodating a preassigned group of base stations and functioning as an exchange, and a service control point at a level higher than these subscriber accommodating centers and managing the location information of all of the mobile terminals present in the mobile switching network.
Assume that a connection request is generated from one mobile terminal X to another mobile terminal Y. This being so, the subscriber accommodating center A inquires at the service control point about the current position of the destination mobile terminal Y through the base station accommodating the mobile terminal X in its service area. The subscriber accommodating center A obtaining the location information corresponding to the inquiry (Y being assumed to be under the subscriber accommodating center B) performs circuit switching to the subscriber accommodating center B shown by the location information. Here, the mobile terminal X is connected to the mobile terminal Y and a communication path is set between the two terminals.
As explained above, by providing a service control point for continually managing the current location information for all mobile terminals at a level higher than all of the subscriber accommodating centers, the subscriber accommodating centers can switch and connect mobile terminals extremely quickly. Note that there are various occasions on which individual mobile terminals register their locations at a service control point, but as an example sometimes a mobile terminal moves from a service area of one base station to a service area of another base station.
In this way, in a mobile switching network, there are both the inherent communication traffic for connecting mobile terminals and communicating between the two and control traffic for managing the location information between the service control point and the subscriber accommodating centers (registering locations and inquiring about location information).
When the number of subscribers of mobile terminals in a mobile switching network is small, the control traffic is small compared with the communication traffic and does not pose that much of a problem. In recent years, however, the number of subscribers of mobile terminals has sharply increased and a large amount of control traffic has been generated. The reason is that a subscriber accommodating center registers a location at the service control point unconditionally and immediately at every opportunity for registration of location regardless of the intent of the user of the mobile terminal.
Therefore, unnecessary control traffic having no relation with the inherent communication traffic has sharply risen in the mobile switching network and the load on the mobile switching network as a whole has increased. This has created a problem.
The present invention was made in consideration of the above problem and has as its object the realization of a location information management system able to reduce the control traffic particularly generated for location registration and as a result reduce the load of the mobile switching network as a whole.
The present invention proposes the following techniques to achieve this object:
First, the method upon which the present invention is predicated is a method of management of location information for a mobile terminal in a mobile switching network having a subscriber accommodating center accommodating a mobile terminal through a base station and a service control point at a level higher than the subscriber accommodating center and managing the current location of all mobile terminals. Here, the present invention is characterized by fixing the location information for a mobile terminal at the service control point in accordance with a request from the subscriber of the mobile terminal and having the subscriber accommodating center having the mobile terminal under it stop location registration for the mobile terminal to the subscriber accommodating center.
Further, the invention is characterized by having a subscriber accommodating center receiving a request for fixing the location information from the subscriber of the mobile terminal manage the location information of the mobile terminal on its own.
In this way, the management of the location information of a mobile terminal issuing a request for fixing its location information is left to the designated subscriber accommodating center related to the request and part of the management of the location information originally performed by the service control point is shared with the subscriber accommodating center side. As a result, the load on the mobile switching network as a whole is lightened and effective use can be made of limited resources.